In recent years, a heterogeneous network has been proposed as a next-generation communication network. The heterogeneous network is a network in which a plurality of kinds of small-to-medium-sized base stations coexist in a macro cell by performing underlay transmission or spectrum sharing. The small-to-medium-sized base stations involve a RRH (Remote RadioHead) cell base station, a hotzone base station (Pico/micro cell eNB), a femtocell base station (Home eNB), a relay node (relay base station) and the like.
In such a heterogeneous network, there is a concern that, when different base stations, such as a macro cell base station and a femtocell base station, for example, use the same frequency, improvement of an area capacity is hindered due to the occurrence of interference. Regarding such a concern, Patent Literature 1 and Patent Literature 2, for example, disclose techniques to overcome the interference issue between different transmitting devices.